The provision of lubrication to a particular location in an apparatus, such as a knitting machine, loom, or the like, is often required. Such lubrication is often provided by a lubricant mist directed towards the targeted area, but the stream is often difficult to direct with accuracy. The lubricant provided by a mist system also often coagulates into drops of various sizes. The presence of a spray of drops having a range of sizes impedes control over the amount of lubricant dispersed and its accurate delivery. Other systems dispense a pulsed series of lubricant “slugs” or drops of varying size.
In U.S. Pat. No. 5,639,028 to the present inventor and assignee, an improved nozzle apparatus for use in lubricant mist systems is disclosed. The nozzle set forth therein generates a lubricant stream of small, consistently sized drops that can be accurately directed to a part to be lubricated. Dripping from the nozzle is substantially eliminated, and the nozzle can be used over a wide range of air pressures, including reduced airflow lubrication systems of the aerosol type.
Mist generator systems in which the nozzle of the '028 Patent are employed may have a plurality of nozzles connected to a single generator, with the number of nozzles approaching 30 in number. With increasing energy costs, the cost of providing compressed air to such a plurality of nozzles can be a considerable operational expense. While limiting the amount of air passing through the nozzle would appear to be an obvious solution to such increasing costs, insufficient extraction of lubricant from the aerosol can occur as the air pressure is lowered, leading to excessive lubricant loss and thus mitigating the value of the nozzle apparatus.
The cycling of air through a plurality of nozzles can also conserve the amount of air required. U.S. Pat. No. 6,571,918 discloses a lubricant distributor that meters lubricant into precise individual volume amounts and directs individual volumes to a distribution and spray system. Such cycling systems can lessen air costs, but can lead to lubricant accumulation and run-off through a nozzle when the airflow is either off or below the designed operational threshold pressure for the nozzle. Such run-off results in lubricant loss as well as insufficient lubrication for the targeted area.
It is accordingly a purpose of the present invention to provide a new and improved nozzle assembly particularly adapted for use in reduced airflow situations in oil mist lubrication systems of the type disclosed in the '028 Patent.
A further purpose of the present invention is to provide a nozzle of the general type disclosed in the '028 Patent in which lubricant loss is substantially lessened, if not eliminated, during low airflow and no airflow periods.
Yet a further purpose of the present invention is to provide an emitter head for mist lubrication nozzles, such as those of the type set forth in the '028 Patent, that allows the nozzle to meet the aforementioned purposes and goals.
Yet a further purpose of the present invention is to provide a nozzle and emitter head which are of simple and economical construction, and which can be used in connection with existing lubricator equipment, including those of the type utilizing a cycling feed-type metering system, such as set forth in U.S. Pat. No. 6,571,918.